1. Field of Invention
The present invention relates to a hospital bed and, more particularly, to a hospital bed equipped with a reliable linkage unit for linking a backrest unit to a leg support unit.
2. Related Prior Art
A hospital bed may include a manual mechanism operable to lift a backrest unit and a leg support unit or put them in a horizontal position to make a patient feel comfortable while sitting or lying. The manual mechanism includes a crank connected to the backrest unit and another crank connected to the leg support unit. The patient has to operate the cranks when he or she is alone. The patient has to get out of the hospital bed to operate the cranks and then get in the hospital bed several times until he or she reaches a right angle for the backrest unit and another right angle for the leg support unit. Obviously, the manual operation is inconvenient for the patient. The manual operation is very difficult if not impossible for a very sick or seriously injured patient.
As disclosed in Taiwanese Patent Nos. 342674 and 382943, a hospital bed includes a backrest unit, a leg support unit, an electric mechanism for driving the backrest unit, and a cable for connecting the leg support unit to the back rest unit so that the leg support unit is moved together with the backrest unit. The operation of the electric mechanism is convenient. However, the cable suffers elastic fatigue after some time of use, thereby jeopardizing the movement of the foot support unit.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.